As described in Talpir, R. et al. (1994) Tetrahedron Lett. 35:4453-6 and in international patent application PCT/GB96/00942 published Oct. 24, 1996 under number WO96/33211, the compound hemiasterlin may be obtained from marine sponges or synthesized. As set forth in PCT/GB96/00942, hemiasterlin and the synthetic analogs described therein are cytotoxic and anti-mitotic.
Compounds that differ from hemiasterlin in the region of the indole moiety of hemiasterlin are novel. It has now been found that analogs of hemiasterlin wherein the indole moiety of hemiasterlin has been deleted or replaced demonstrate potent anti-mitotic and cytotoxic activity.